The present invention relates generally to implement guidance systems and more specifically to forming guidance furrows for establishing an accurate reference for such systems.
Automatic guidance or steering systems for row crop implements have been available in various forms for many years. A majority of such systems rely on a preestablished groove or furrow in the ground to provide a reference location from which the implement or towing vehicle is guided. The success or failure of these systems depends largely on the quality of the furrow at the time it is to be sensed, which can be weeks or even months after it is formed. The furrow must be able to withstand heavy rains and also must be free of clods, rocks and other obstacles. The size and integrity of the furrow must be sufficient to guide whatever type of furrow sensor is utilized with the guidance system. An inadequate furrow can render the guidance system useless and result in crop damage when the implement is guided or steered improperly with respect to the rows of crop.
Numerous furrow-forming devices are available but most are not entirely satisfactory. A single rigid or spring trip shank mounted on the implement tends to turn up clods which roll back into the furrow, and the loose sides of the furrow formed by the shank do not weather well in heavy rains. V-shaped rubber tires or wheels have been used but do not penetrate well in hard soil. In addition, loose soil often flows around the wheel hub and fills the furrow.
To aid soil penetration, some available furrowers are rigidly mounted on the implement frame, and therefore obstacles such as rocks encountered by the furrower can actually lift the entire implement. Implement depth control can therefore be adversely affected, and the furrower is subjected to heavy loading.
When the furrower is mounted on a steered or guided implement and is utilized to reform a furrow, transverse movements of the implement caused by the guidance system or by the driver's steering corrections cause the remade furrow to deviate from a path substantially parallel to the row. Consequently, the reformed furrow provides a less than optimum reference for future guidance. The deviation from a desired path is particularly noticeable when the furrower is attached to a rear-mounted implement because initial steering corrections can momentarily move the implement further off-center with respect to the rows.
It is therefore an object of the present invention to provide an improved method and apparatus for forming a guidance furrow. It is another object to provide such a method and apparatus which overcomes the above-mentioned problems.
It is a further object of the invention to provide an improved method and apparatus for forming a guidance furrow which can withstand heavy rains. It is yet another object to provide such a method and apparatus for forming a furrow relatively free from loose dirt, clods and rocks or other obstacles.
It is yet another object of the present invention to provide an improved method and apparatus for establishing a guidance furrow from an implement which itself is guided or steered by a guidance furrow.
It is still another object to provide a method and apparatus for establishing an accurate guidance furrow from an implement, wherein movements of the implement transverse to the forward direction are averaged out to prevent corresponding deviations in the furrow.
It is a further object of the invention to provide an improved furrowing device which penetrates hard soils better than at least some of the previously available devices and which provides a high quality, long-lasting furrow with well packed sides and edges. It is another object to provide such a furrowing device which can still easily move over obstacles such as rocks.
In accordance with the above objects, a furrowing tool is provided, including a fore-and-aft frame supporting a soil-penetrating shovel ahead of a vertically rockable furrow-forming wheel. The shovel loosens the soil, and the wheel forms a furrow with packed sides. Depth bands or the like packing elements extend outwardly from the rim of the wheel to pack the edges of the furrow and to prevent loose dirt, and clods and other obstacles from falling into the furrow. A high quality, long-lasting furrow is established.
When utilized to remake a furrow, the frame is pivotally connected to the implement for rocking transversely to permit the shovel and furrow-forming tool to trail the implement and therefore average out transverse movements caused by the implement guidance system or operator steering corrections. The remade furrow therefore provides a more accurate reference for future operations.
These and other objects, features and advantages of the present invention will become apparent from the description which follows and from the drawings.